doepfer/a-188-9
A-188-9 High Speed VCO / PLL
Precision audio VCO with an integrated PLL (phase-locked loop) that multiplies the VCO frequency by 32, primarily for driving BBD delay modules. Outputs sawtooth, triangle, and rectangle waveforms; operates in Audio VCO or High-Speed VCO mode.1007
Capabilities 4
- BBD Clock Sourcebbd-clock
- Primary application is as a clock source for BBD delay modules (A-188-1/2), enabling 1V/oct pitch-tracked Karplus-Strong synthesis over a wide range.1007
- PLLpll
- Integrated PLL multiplies audio VCO frequency by 32 (optimized); jumper-selectable factors of 8, 16, or 64 also available.1007
- Pulse Width Modulationpwm
- Rectangle output supports pulse width modulation via the PW trimmer knob.1007
- Voltage-Controlled Oscillatorvco
- Precision audio VCO with 1V/oct tracking; outputs sawtooth, triangle, and rectangle waveforms in both Audio VCO and High-Speed VCO modes.1007
Jacks 6 (2 in / 4 out)
| Name | Signal | Voltage | Description |
|---|---|---|---|
| Inputs (2) | |||
| 1V | cv | — | 1V/octave pitch tracking input for the VCO frequency.1007 |
| CV | cv | — | Frequency control CV input with dedicated attenuator knob.1007 |
| Outputs (4) | |||
| HSVCO Out | clock | -2.5V to 2.5V | High-speed PLL output; rectangle waveform at ~15 kHz–500 kHz (in HSVCO mode), approximately 5Vpp. Not usable in Audio VCO mode.1007 |
| Rectangle Out | audio | -3.5V to 3.5V | Rectangle (pulse) output of the audio VCO with pulse width controllable by the PW knob; approximately 7Vpp output level.1007 |
| Sawtooth Out | audio | -3.5V to 3.5V | Sawtooth output of the audio VCO; approximately 7Vpp output level.1007 |
| Triangle Out | audio | -3.5V to 3.5V | Triangle output of the audio VCO; approximately 7Vpp output level.1007 |
Parameters 6
| Name | Type | Range | Behavior |
|---|---|---|---|
| CV | knob | — | Attenuator for the CV frequency control input jack.1007 |
| Fine | knob | — | Fine frequency adjustment; small trimmer-style control without a knob.1007 |
| Frq | knob | — | Coarse frequency control. In HSVCO mode, covers ~13 kHz to 450 kHz at the HSVCO output and ~400 Hz to 14 kHz at the VCO outputs. In Audio VCO mode, covers ~12 Hz to 400 Hz at the VCO outputs.1007 |
| PW | knob | — | Sets the pulse width of the rectangle output. In HSVCO mode, must be positioned within the range marked 'HSVCO'. Small trimmer-style control without a knob.1007 |
| Range | switch | — | Two-position switch selecting the operating mode: upper position is Audio VCO (~15 Hz–6 kHz), lower position is High-Speed VCO (~15 kHz–500 kHz PLL output, ~500 Hz–15 kHz audio VCO outputs simultaneously).1007 |
| Slew | switch | — | Three-position switch controlling PLL slew time: upper = medium (M), center = fast (F), lower = slow (S). Sets how quickly the PLL tracks VCO frequency changes, trading off tracking speed against residual frequency ripple.1007 |
Firmware history 0 versions
No firmware history recorded.
References 1
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[1007]
Doepfer A-188-9 High Speed VCO / PLL product pageproduct_page● verified 2026-05-27